Preparation method, product, and application of iron-cobalt fenton-like catalyst

Abstract

A preparation method of an iron-cobalt fenton-like catalyst includes steps of: adopting FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O as reaction precursors, KBH.sub.4 as a reaction reducing agent, and polyvinyl pyrrolidone (PVP) as a surface protecting agent; preparing with a liquid phase reduction method; and after aging, suction filtration, washing, and vacuum drying, obtaining a product of the iron-cobalt fenton-like catalyst. The iron-cobalt fenton-like catalyst has a fast reaction, a relatively high treatment efficiency and a relatively wide adaptability. Moreover, an application of the iron-cobalt fenton-like catalyst in an industrial wastewater treatment is provided.

Claims

1. A preparation method of an iron-cobalt fenton-like catalyst, comprising steps of: respectively preparing aqueous solutions of FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O, wherein a molar concentration ratio of Fe.sup.2+ to Co.sup.2+ is 1:1-10:1; the FeCl.sub.2.4H.sub.2O and the CoCl.sub.7.6H.sub.2O serve as reaction precursors; adding 2-10 ml of polyvinyl pyrrolidone (PVP) having a concentration of 5 g/L, so as to obtain a first mixed solution I, wherein the PVP serves as a surface protecting agent; weighing 100 ml of deionized water, adding NaOH into the deionized water for adjusting a pH value of the deinoized water to 11.0-12.0, and then adding 1-5 g of KBH.sub.4 to prepare a second mixed solution II, wherein the KBH.sub.4 serves as a reaction reducing agent; dropping the second mixed solution II into the first mixed solution I with a reaction temperature controlled at 505 C., a dropping speed controlled at 15-50 r/min by a peristaltic pump, and a stirring speed controlled at 400-900 r/min by a mechanical stirrer, and then generating a black precipitate; after finishing dropping the second mixed solution II of the KBH.sub.4 and the NaOH, stirring an obtained third mixed solution for 10-40 min, and aging for 0.5-2 h; and, after suction filtration, washing, and vacuum drying, obtaining the iron-cobalt fenton-like catalyst.

2. A method for treating industrial wastewater with an iron-cobalt fenton-like catalyst, comprising steps of: (1) collecting a wastewater sample to be treated, and adjusting a pH value of the wastewater sample to 2.00.1; (2) adding an H.sub.2O.sub.2 solution having a content of 30% into the wastewater sample, and then adding the iron-cobalt fenton-like catalyst into the wastewater sample, so as to obtain a mixed solution; (3) fully reacting the mixed solution with a stirring speed controlled at 200-400 r/min for 5-20 min, and controlling a pH value of the mixed solution at a range of 2.00.5 during reacting; (4) adjusting a pH value of a reacted solution to being larger than or equal to 10.0, and heating an adjusted solution in a water bath at a temperature of 50 C. for 0.5-1 h; and (5) adjusting a pH value of a heated solution to 7.0, and standing for precipitating, wherein a supernatant of a precipitated solution is a treated effluent.

3. The method for treating the industrial wastewater with the iron-cobalt fenton-like catalyst, as recited in claim 2, wherein: in the step (2), a volume ratio of the wastewater sample to the H.sub.2O.sub.2 solution is 500:1-1000:1, and a mass ratio of the iron-cobalt fenton-like catalyst to the H.sub.2O.sub.2 solution is 5:1-10:1.

4. The method for treating the industrial wastewater with the iron-cobalt fenton-like catalyst, as recited in claim 2, wherein: the industrial wastewater is acrylon wastewater, dye wastewater, petrochemical wastewater, phenol-acetone production wastewater, acrylonitrile butadiene styrene (ABS) synthetic resin wastewater, or acrylic acid production wastewater.

5. The method for treating the industrial wastewater with the iron-cobalt fenton-like catalyst, as recited in claim 3, wherein: the industrial wastewater is acrylon wastewater, dye wastewater, petrochemical wastewater, phenol-acetone production wastewater, acrylonitrile butadiene styrene (ABS) synthetic resin wastewater, or acrylic acid production wastewater.

6. The method for treating the industrial wastewater with the iron-cobalt fenton-like catalyst, as recited in claim 2, wherein the iron-cobalt fenton-like catalyst is prepared by following steps of: adopting FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O as reaction precursors, KBH.sub.4 as a reaction reducing agent, and polyvinyl pyrrolidone (PVP) as a surface protecting agent; preparing with a liquid phase reduction method; and after aging, suction filtration, washing, and vacuum drying, obtaining the iron-cobalt fenton-like catalyst.

7. The method for treating the industrial wastewater with the iron-cobalt fenton-like catalyst, as recited in claim 3, wherein the iron-cobalt fenton-like catalyst is prepared by following steps of: adopting FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O as reaction precursors, KBH.sub.4 as a reaction reducing agent, and polyvinyl pyrrolidone (PVP) as a surface protecting agent; preparing with a liquid phase reduction method; and after aging, suction filtration, washing, and vacuum drying, obtaining the iron-cobalt fenton-like catalyst.

8. The method for treating the industrial wastewater with the iron-cobalt fenton-like catalyst, as recited in claim 4, wherein the iron-cobalt fenton-like catalyst is prepared by following steps of: adopting FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O as reaction precursors, KBH.sub.4 as a reaction reducing agent, and polyvinyl pyrrolidone (PVP) as a surface protecting agent; preparing with a liquid phase reduction method; and after aging, suction filtration, washing, and vacuum drying, obtaining the iron-cobalt fenton-like catalyst.

9. The method for treating the industrial wastewater with the iron-cobalt fenton-like catalyst, as recited in claim 5, wherein the iron-cobalt fenton-like catalyst is prepared by following steps of: adopting FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O as reaction precursors, KBH.sub.4 as a reaction reducing agent, and polyvinyl pyrrolidone (PVP) as a surface protecting agent; preparing with a liquid phase reduction method; and after aging, suction filtration, washing, and vacuum drying, obtaining the iron-cobalt fenton-like catalyst.

10. The method for treating the industrial wastewater with the iron-cobalt fenton-like catalyst, as recited in claim 2, wherein the iron-cobalt fenton-like catalyst is prepared by following steps of: respectively preparing aqueous solutions of FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O, wherein a molar concentration ratio of Fe.sup.2+ to Co.sup.2+ is 1:1-10:1, and adding 2-10 ml of a surface protecting agent of polyvinyl pyrrolidone (PVP) having a concentration of 5 g/L, so as to obtain a first mixed solution I; weighing 100 ml of deionized water, adding NaOH into the deionized water for adjusting a pH value of the deinoized water to 11.0-12.0, and then adding 1-5 g of KBH.sub.4 to prepare a second mixed solution II; dropping the second mixed solution II into the first mixed solution I with a reaction temperature controlled at 505 C., a dropping speed controlled at 15-50 r/min by a peristaltic pump, and a stirring speed controlled at 400-900 r/min by a mechanical stirrer, and then generating a black precipitate; after finishing dropping the second mixed solution II of the KBH.sub.4 and the NaOH, continue stirring for 10-40 min, and aging for 0.5-2 h; and, after suction filtration, washing, and vacuum drying, obtaining the iron-cobalt fenton-like catalyst.

11. The method for treating the industrial wastewater with the iron-cobalt fenton-like catalyst, as recited in claim 3, wherein the iron-cobalt fenton-like catalyst is prepared by following steps of: respectively preparing aqueous solutions of FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O, wherein a molar concentration ratio of Fe.sup.2+ to Co.sup.2+ is 1:1-10:1, and adding 2-10 ml of a surface protecting agent of polyvinyl pyrrolidone (PVP) having a concentration of 5 g/L, so as to obtain a first mixed solution I; weighing 100 ml of deionized water, adding NaOH into the deionized water for adjusting a pH value of the deinoized water to 11.0-12.0, and then adding 1-5 g of KBH.sub.4 to prepare a second mixed solution II; dropping the second mixed solution II into the first mixed solution I with a reaction temperature controlled at 505 C., a dropping speed controlled at 15-50 r/min by a peristaltic pump, and a stirring speed controlled at 400-900 r/min by a mechanical stirrer, and then generating a black precipitate; after finishing dropping the second mixed solution II of the KBH.sub.4 and the NaOH, continue stirring for 10-40 min, and aging for 0.5-2 h; and, after suction filtration, washing, and vacuum drying, obtaining the iron-cobalt fenton-like catalyst.

12. The method for treating the industrial wastewater with the iron-cobalt fenton-like catalyst, as recited in claim 4, wherein the iron-cobalt fenton-like catalyst is prepared by following steps of: respectively preparing aqueous solutions of FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O, wherein a molar concentration ratio of Fe.sup.2+ to Co.sup.2+ is 1:1-10:1, and adding 2-10 ml of a surface protecting agent of polyvinyl pyrrolidone (PVP) having a concentration of 5 g/L, so as to obtain a first mixed solution I; weighing 100 ml of deionized water, adding NaOH into the deionized water for adjusting a pH value of the deinoized water to 11.0-12.0, and then adding 1-5 g of KBH.sub.4 to prepare a second mixed solution II; dropping the second mixed solution II into the first mixed solution I with a reaction temperature controlled at 505 C., a dropping speed controlled at 15-50 r/min by a peristaltic pump, and a stirring speed controlled at 400-900 r/min by a mechanical stirrer, and then generating a black precipitate; after finishing dropping the second mixed solution II of the KBH.sub.4 and the NaOH, continue stirring for 10-40 min, and aging for 0.5-2 h; and, after suction filtration, washing, and vacuum drying, obtaining the iron-cobalt fenton-like catalyst.

13. The method for treating the industrial wastewater with the iron-cobalt fenton-like catalyst, as recited in claim 5, wherein the iron-cobalt fenton-like catalyst is prepared by following steps of: respectively preparing aqueous solutions of FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O, wherein a molar concentration ratio of Fe.sup.2+ to Co.sup.2+ is 1:1-10:1, and adding 2-10 ml of a surface protecting agent of polyvinyl pyrrolidone (PVP) having a concentration of 5 g/L, so as to obtain a first mixed solution I; weighing 100 ml of deionized water, adding NaOH into the deionized water for adjusting a pH value of the deinoized water to 11.0-12.0, and then adding 1-5 g of KBH.sub.4 to prepare a second mixed solution II; dropping the second mixed solution II into the first mixed solution I with a reaction temperature controlled at 505 C., a dropping speed controlled at 15-50 r/min by a peristaltic pump, and a stirring speed controlled at 400-900 r/min by a mechanical stirrer, and then generating a black precipitate; after finishing dropping the second mixed solution II of the KBH.sub.4 and the NaOH, continue stirring for 10-40 min, and aging for 0.5-2 h; and, after suction filtration, washing, and vacuum drying, obtaining the iron-cobalt fenton-like catalyst.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The FIGURE is a sketch view of measured results of a wastewater absorbance before and after treating according to a second preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Example 1

(2) A preparation method of an iron-cobalt fenton-like catalyst comprises steps of: weighing a certain amount of FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O, and preparing aqueous solutions respectively having a Fe.sup.2+ concentration of 0.5 mol/L and a Co.sup.2+ concentration of 0.5 mol/L; respectively putting 100 ml of the two aqueous solutions into a three-necked flask, and adding 8 ml of a surface protecting agent of polyvinyl pyrrolidone (PVP) having a concentration of 5 g/L into the three-necked flask, so as to obtain a first mixed solution I; adding 2 g of KBH.sub.4 into 100 ml of an NaOH aqueous solution having a pH value of 11.0-12.0, so as to prepare a second mixed solution II; dropping the second mixed solution II into the three-necked flask for mixing with the first mixed solution I with a reaction temperature controlled at 50 C., a dropping speed controlled at 30 r/min by a peristaltic pump, and a stirring speed controlled at 600 r/min by a mechanical stirrer, and then generating a black precipitate; after finishing dropping the second mixed solution II of the KBH.sub.4 and NaOH, continue stirring for 20 min, and aging for 1 h; and, after suction filtration, washing, and vacuum drying, obtaining a product of the iron-cobalt fenton-like catalyst.

(3) An advanced treatment method for an acrylon biochemical effluent with the catalyst obtained by the above preparation method comprises steps of:

(4) (1) collecting 400 ml of a water sample to be treated which is raw water of the acrylon biochemical effluent having a pH value of 6.8-7.5, and adjusting the pH value of the water sample to 2.0 with an H.sub.2SO.sub.4 solution;

(5) (2) firstly adding 0.5 ml of an H.sub.2O.sub.2 solution having a content of 30% into the water sample, and then adding 1.1472 g of the iron-cobalt fenton-like catalyst into the water sample, so as to obtain a first mixed solution;

(6) (3) stirring the first mixed solution with a stirring speed of 200 r/min, controlling a pH value of the first mixed solution at a range of 2.00.5 with the H.sub.2SO.sub.4 solution during reacting, and reacting for 10 min;

(7) (4) adjusting a pH value of a second mixed solution obtained by the step (3) to being larger than or equal to 10.0 with an NaOH solution, and then heating an adjusted second mixed solution in a water bath at a temperature of 50 C. for 1 h; and

(8) (5) after cooling a third mixed solution obtained by the step (4), adjusting a pH value of the third mixed solution to 7.0 with the NaOH solution, and staying for precipitating, wherein a supernatant of a precipitated solution is a treated effluent and a COD.sub.Cr value in the water sample before and after treating is showed in Table 1.

(9) TABLE-US-00001 TABLE 1 Quality of water sample before and after treating COD.sub.Cr (mg/L) COD.sub.Cr removal rate (%) Before treating 232.6 After treating 86.1 63.0

Example 2

(10) A preparation method of an iron-cobalt fenton-like catalyst comprises steps of: weighing a certain amount of FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O, and preparing aqueous solutions respectively having a Fe.sup.2+ concentration of 0.5 mol/L and a Co.sup.2+ concentration of 0.05 mol/L; respectively putting 100 ml of the two aqueous solutions into a three-necked flask, and adding 10 ml of a surface protecting agent of PVP having a concentration of 5 g/L into the three-necked flask; adding 1 g of KBH.sub.4 into 100 ml of an NaOH aqueous solution having a pH value of 11.0-12.0, so as to prepare a mixed solution; dropping the mixed solution into the three-necked flask with a reaction temperature controlled at 45 C., a dropping speed controlled at 15 r/min by a peristaltic pump, and a stirring speed controlled at 400 r/min by a mechanical stirrer, and then generating a black precipitate; after finishing dropping the mixed solution of the KBH.sub.4 and NaOH, continue stirring for 10 min, and aging for 2 h; and, after suction filtration, washing, and vacuum drying, obtaining a product of the iron-cobalt fenton-like catalyst.

(11) A method for treating dye wastewater with the product obtained by the above preparation method comprises steps of:

(12) (1) preparing Basic Red 46 dye wastewater which has a concentration of 200 mg/L and a pH value of 4.0-4.5, weighing 400 ml of the Basic Red 46 dye wastewater to serve as a water sample, and adjusting a pH value of the water sample to 2.1 with an H.sub.2SO.sub.4 solution;

(13) (2) firstly adding 0.8 ml of an H.sub.2O.sub.2 solution having a content of 30% into the water sample, and then adding 2.6960 g of the iron-cobalt fenton-like catalyst into the water sample, so as to obtain a first mixed solution;

(14) (3) fully mixing the first mixed solution with a stirring speed controlled at 400 r/min, controlling a pH value of the first mixed solution at a range of 2.00.5 with the H.sub.2SO.sub.4 solution during reacting, and reacting for 20 min;

(15) (4) adjusting a pH value of a second mixed solution obtained by the step (3) to being larger than or equal to 10.0 with an NaOH solution, and then heating an adjusted second mixed solution in a water bath at a temperature of 50 C. for 1 h; and

(16) (5) after cooling a third mixed solution obtained by the step (4), adjusting a pH value of the third mixed solution to 7.0 with the NaOH solution, and staying for precipitating, wherein a supernatant of a precipitated solution is a treated effluent; a change of a COD.sub.Cr value in the water sample before and after treating is showed in Table 2; and measured results of an absorbance of the water sample before and after treating are showed in the FIGURE.

(17) TABLE-US-00002 TABLE 2 Quality of water sample before and after treating COD.sub.Cr (mg/L) COD.sub.Cr removal rate (%) Before treating 272.6 After treating 71.2 73.88

Example 3

(18) A preparation method of an iron-cobalt fenton-like catalyst comprises steps of: weighing a certain amount of FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O, and preparing aqueous solutions respectively having a Fe.sup.2+ concentration of 0.5 mol/L and a Co.sup.2+ concentration of 0.1 mol/L; respectively putting 100 ml of the two aqueous solutions into a three-necked flask, and adding 2 ml of a surface protecting agent of PVP having a concentration of 5 g/L into the three-necked flask; adding 5 g of KBH.sub.4 into 100 ml of an NaOH aqueous solution having a pH value of 11.0-12.0, so as to prepare a mixed solution; dropping the mixed solution into the three-necked flask with a reaction temperature controlled at 55 C., a dropping speed controlled at 50 r/min by a peristaltic pump, and a stirring speed controlled at 900 r/min by a mechanical stirrer, and then generating a black precipitate; after finishing dropping the mixed solution of the KBH.sub.4 and NaOH, continue stirring for 40 min, and aging for 0.5 h; and, after suction filtration, washing, and vacuum drying, obtaining a product of the iron-cobalt fenton-like catalyst.

(19) An advanced treatment method for petrochemical industry park wastewater with the product obtained by the above preparation method comprises steps of:

(20) (1) weighing 400 ml of a water sample to be treated which is petrochemical wastewater having a pH value of 6.0-7.0, and adjusting a pH value of the water sample to 2.0 with an H.sub.2SO.sub.4 solution;

(21) (2) firstly adding 0.4 ml of an H.sub.2O.sub.2 solution having a content of 30% into the water sample, and then adding 0.6740 g of the iron-cobalt fenton-like catalyst into the water sample, so as to obtain a first mixed solution;

(22) (3) fully mixing the first mixed solution with a stirring speed controlled at 300 r/min, controlling a pH value of the first mixed solution at a range of 2.00.5 with the H.sub.2SO.sub.4 solution during reacting, and reacting for 5 min;

(23) (4) adjusting a pH value of a second mixed solution obtained by the step (3) to being larger than or equal to 10.0 with an NaOH solution, and then heating an adjusted second mixed solution in a water bath at a temperature of 50 C. for 1 h; and

(24) (5) after cooling a third mixed solution obtained by the step (4), adjusting a pH value of the third mixed solution to 7.0 with the NaOH solution, and staying for precipitating, wherein a supernatant of a precipitated solution is a treated effluent and a change of a COD.sub.Cr value in the water sample before and after treating is showed in Table 3.

(25) TABLE-US-00003 TABLE 3 Quality of water sample before and after treating COD.sub.Cr (mg/L) COD.sub.Cr removal rate (%) Before treating 67.6 After treating 29.1 57.0

Example 4

(26) A preparation method of an iron-cobalt fenton-like catalyst comprises steps of: weighing a certain amount of FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O, and preparing aqueous solutions respectively having a Fe.sup.2+ concentration of 0.5 mol/L and a Co.sup.2+ concentration of 0.25 mol/L; respectively putting 100 ml of the two aqueous solutions into a three-necked flask, and adding 5 ml of a surface protecting agent of PVP having a concentration of 5 g/L into the three-necked flask; adding 4 g of KBH.sub.4 into 100 ml of an NaOH aqueous solution having a pH value of 11.0-12.0, so as to prepare a mixed solution; dropping the mixed solution into the three-necked flask with a reaction temperature controlled at 50 C., a dropping speed controlled at 40 r/min by a peristaltic pump, and a stirring speed controlled at 800 r/min by a mechanical stirrer, and then generating a black precipitate; after finishing dropping the mixed solution of the KBH.sub.4 and NaOH, continue stirring for 30 min, and aging for 1.5 h; and, after suction filtration, washing, and vacuum drying, obtaining a product of the iron-cobalt fenton-like catalyst.

(27) A method for pretreating phenol-acetone production wastewater with the product obtained by the above preparation method comprises steps of:

(28) (1) weighing 400 ml of a water sample to be treated which is the phenol-acetone production wastewater having a pH value of about 12.0, and adjusting a pH value of the water sample to 1.9 with an H.sub.2SO.sub.4 solution;

(29) (2) firstly adding 0.67 ml of an H.sub.2O.sub.2 solution having a content of 30% into the water sample, and then adding 1.8603 g of the iron-cobalt fenton-like catalyst into the water sample, so as to obtain a first mixed solution;

(30) (3) fully mixing the first mixed solution with a stirring speed controlled at 200 r/min, controlling a pH value of the first mixed solution at a range of 2.00.5 with the H.sub.2SO.sub.4 solution during reacting, and reacting for 10 min;

(31) (4) adjusting a pH value of a second mixed solution obtained by the step (3) to being larger than or equal to 10.0 with an NaOH solution, and then heating an adjusted second mixed solution in a water bath at a temperature of 50 C. for 1 h; and

(32) (5) after cooling a third mixed solution obtained by the step (4), adjusting a pH value of the third mixed solution to 7.0 with the NaOH solution, and staying for precipitating, wherein a supernatant of a precipitated solution is a treated effluent and a change of a COD.sub.Cr value in the water sample before and after treating is showed in Table 4.

(33) TABLE-US-00004 TABLE 4 Quality of water sample before and after treating COD.sub.Cr (mg/L) COD.sub.Cr removal rate (%) Before treating 2326 After treating 1352 41.9

Example 5

(34) A preparation method of an iron-cobalt fenton-like catalyst comprises steps of: weighing a certain amount of FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O, and preparing aqueous solutions respectively having a Fe.sup.2+ concentration of 0.5 mol/L and a Co.sup.2+ concentration of 0.5 mol/L; respectively putting 100 ml of the two aqueous solutions into a three-necked flask, and adding 6 ml of a surface protecting agent of PVP having a concentration of 5 g/L into the three-necked flask; adding 3 g of KBH.sub.4 into 100 ml of an NaOH aqueous solution having a pH value of 11.0-12.0, so as to prepare a mixed solution; dropping the mixed solution into the three-necked flask with a reaction temperature controlled at 55 C., a dropping speed controlled at 20 r/min by a peristaltic pump, and a stirring speed controlled at 400 r/min by a mechanical stirrer, and then generating a black precipitate; after finishing dropping the mixed solution of the KBH.sub.4 and NaOH, continue stirring for 10 min, and aging for 1 h; and, after suction filtration, washing, and vacuum drying, obtaining a product of the iron-cobalt fenton-like catalyst.

(35) A method for pretreating acrylic acid production wastewater with the product obtained by the above preparation method comprises steps of:

(36) (1) weighing 400 ml of a water sample to be treated which is the acrylic acid production wastewater having a pH value of 5.0-6.0, and adjusting a pH value of the water sample to 2.0 with an H.sub.2SO.sub.4 solution;

(37) (2) firstly adding 0.5 ml of an H.sub.2O.sub.2 solution having a content of 30% into the water sample, and then adding 1.1472 g of the iron-cobalt fenton-like catalyst into the water sample, so as to obtain a first mixed solution;

(38) (3) fully mixing the first mixed solution with a stirring speed controlled at 400 r/min, controlling a pH value of the first mixed solution at a range of 2.00.5 with the H.sub.2SO.sub.4 solution during reacting, and reacting for 20 min;

(39) (4) adjusting a pH value of a second mixed solution obtained by the step (3) to being larger than or equal to 10.0 with an NaOH solution, and then heating an adjusted second mixed solution in a water bath at a temperature of 50 C. for 1 h; and

(40) (5) after cooling a third mixed solution obtained by the step (4), adjusting a pH value of the third mixed solution to 7.0 with the NaOH solution, and staying for precipitating, wherein a supernatant of a precipitated solution is a treated effluent and a change of a COD.sub.Cr value in the water sample before and after treating is showed in Table 5.

(41) TABLE-US-00005 TABLE 5 Quality of water sample before and after treating COD.sub.Cr (mg/L) COD.sub.Cr removal rate (%) Before treating 63349 After treating 34982 44.8

Example 6

(42) A preparation method of an iron-cobalt fenton-like catalyst comprises steps of: weighing a certain amount of FeCl.sub.2.4H.sub.2O and CoCl.sub.2.6H.sub.2O, and preparing aqueous solutions respectively having a Fe.sup.2+ concentration of 0.5 mol/L and a Co.sup.2+ concentration of 0.5 mol/L; respectively putting 100 ml of the two aqueous solutions into a three-necked flask, and adding 10 ml of a surface protecting agent of PVP having a concentration of 5 g/L into the three-necked flask; adding 2 g of KBH.sub.4 into 100 ml of an NaOH aqueous solution having a pH value of 11.0-12.0, so as to prepare a mixed solution; dropping the mixed solution into the three-necked flask with a reaction temperature controlled at 55 C., a dropping speed controlled at 30 r/min by a peristaltic pump, and a stirring speed controlled at 900 r/min by a mechanical stirrer, and then generating a black precipitate; after finishing dropping the mixed solution of the KBH.sub.4 and NaOH, continue stirring for 40 min, and aging for 1 h; and, after suction filtration, washing, and vacuum drying, obtaining a product of the iron-cobalt fenton-like catalyst.

(43) A method for pretreating acrylonitrile butadiene styrene (ABS) synthetic resin wastewater with the product obtained by the above preparation method comprises steps of:

(44) (1) weighing 400 ml of a water sample to be treated which is the ABS synthetic resin wastewater having a pH value of 6.0-7.0, and adjusting a pH value of the water sample to 2.0 with an H.sub.2SO.sub.4 solution;

(45) (2) firstly adding 0.4 ml of an H.sub.2O.sub.2 solution having a content of 30% into the water sample, and then adding 0.6740 g of the iron-cobalt fenton-like catalyst into the water sample, so as to obtain a first mixed solution;

(46) (3) fully mixing the first mixed solution with a stirring speed controlled at 300 r/min, controlling a pH value of the first mixed solution at a range of 2.00.5 with the H.sub.2SO.sub.4 solution during reacting, and reacting for 5 min;

(47) (4) adjusting a pH value of a second mixed solution obtained by the step (3) to being larger than or equal to 10.0 with an NaOH solution, and then heating an adjusted second mixed solution in a water bath at a temperature of 50 C. for 1 h; and

(48) (5) after cooling a third mixed solution obtained by the step (4), adjusting a pH value of the third mixed solution to 7.0 with the NaOH solution, and staying for precipitating, wherein a supernatant of a precipitated solution is a treated effluent and a change of a COD.sub.Cr value in the water sample before and after treating is showed in Table 6.

(49) TABLE-US-00006 TABLE 6 Quality of water sample before and after treating COD.sub.Cr (mg/L) COD.sub.Cr removal rate (%) Before treating 1108 After treating 698 37.0

(50) One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. It will thus be seen that the objects of the present invention have been fully and effectively accomplished. Its embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

INDUSTRIAL PRACTICABILITY

(51) The iron-cobalt fenton-like catalyst and the preparation method thereof provided by the present invention have a relatively fast treatment speed. When treating the industrial wastewater, a relatively good treatment effect is achieved in a 10-min reaction time. Moreover, the catalyst has a relatively high treatment efficiency. When treating the industrial wastewater, the removal rate of the COD.sub.Cr in the acrylon wastewater with the advanced treatment is above 60%, and the removal rate of the COD.sub.Cr in the self-prepared dye wastewater is above 70%. Furthermore, the catalyst has a wide application range. The catalyst is applicable for not only the advanced treatment of the acrylon wastewater and the dye wastewater, but also the pretreatment and the advanced treatment of the petrochemical wastewater, the phenol-acetone production wastewater, the ABS synthetic resin wastewater, and the acrylic acid production wastewater. The catalyst has the wide market prospect and the strong industrial practicability.